Portable navigation devices are well known, widely used, and are becoming increasingly popular. Navigation Satellite Timing and Ranging Global Positioning System (NAVSTAR GPS, commonly abbreviated as GPS) has become one standard of navigation and timing for myriad civilian and military applications. In particular, handheld and vehicle-mounted GPS units have the ability to determine their position and display maps, routes, and location information. The GPS units may further store one or more positions as navigational references or waypoints for later retrieval and routing.
In addition to providing an absolute Earth location (usually defined at least in terms of latitude, longitude, and altitude), a handheld GPS may further be coupled proximate a rangefinder to determine the position of a distant object. For example U.S. Pat. No. 4,949,089 to Ruszkowski, Jr. discloses a portable target locator system. In particular, the locator system includes a GPS receiver capable of determining the location coordinates of a target locator. A laser rangefinder and digital azimuth and inclination sensor proximate the target locator are then utilized to accurately determine the range, azimuth and inclination of an identified target from the target locator. The rangefinder information may then be processed in conjunction with the location coordinates of the target locator to generate location coordinates for the selected target. A similar system may be employed to collect data for a geographic information system (GIS) database. U.S. Pat. No. 5,528,518 to Bradshaw et al. further discloses that a user may locate an object and then may store objects, features, and attributes selected from a predefined data dictionary for the located object.
GPS units employing voice processing and voice synthesis are known for accepting verbal commands and providing audible output, for example, verbal driving or route instructions. For example, U.S. Pat. No. 6,490,521 to Wiener discloses a subscriber unit including a GPS mechanism to determine subscriber position information and a speech processing mechanism to receive destination information spoken by a subscriber. The subscriber unit transmits the subscriber position and destination information to the service provider, which gathers navigation information including a map and a route from the subscriber position to the specified destination. The service provider transmits the navigation information to the subscriber unit. The subscriber unit conveys the received navigation information to the subscriber via an output mechanism, such as a speech synthesis unit and/or a graphical display.
In addition to driving or route information, a GPS unit may more generally output audiovisual data. U.S. Pat. App. Pub. US 2004/0036649 A1 to Taylor discloses a portable information system that utilizes GPS data as a key to automatically retrieve audiovisual data from a database. For example, during a tour or journey, the portable information system may automatically identify and describe places of interest, landmarks, history of nearby buildings, or locate hotels, hospitals, shops, etc., within a radius from the portable information system. Audible menus and voice commands may allow the portable information system to be operated hand- and eyes-free.
GPS units interoperable with a radio, for example combination GPS/radio units are also known to communicate location information to another GPS/radio unit. U.S. Pat. No. 7,142,900 to Straub discloses a portable GPS/radio unit that communicates information over a wireless radio network with at least one other such GPS/radio unit to share each unit's location. Each GPS/radio unit includes a single, push-to-talk button that may be pressed to both transmit a voice communication and to initiate transmission of location data to other such units within radio range. Each GPS/radio unit may also include a polling function that requests location data from other GPS/radio units, an auxiliary coding system that codes or encrypts all transmitted data, and an emergency message feature that facilities the transmission and receipt of emergency messages.
Handheld and vehicle-mounted GPS units may also display location, waypoints, map information, and the like on graphical displays. For example, U.S. Pat. No. 5,952,959 to Norris discloses a system of GPS devices, each device including a graphical interface to display the relative positions of the GPS devices in relation to each other. Additionally, U.S. Pat. No. 6,850,188 discloses that the perspective or vantage point from which the location data and other information data is graphically displayed may be selected or changed by the user.
The present inventors have identified a need for an improved system and method to determine locations, navigate, and communicate location information.